Changing demographics in the U.S. suggest that dementia will become "the epidemic of the 21st century" (Bachman et al., 1992, p. 21). In Alzheimer's Disease (AD), the leading form of dementia, research has focused on the cognitive and neurocognitive domains, with relatively little attention to functional capacities. While efforts by Beck et al. (1988, 1989, 1991), and others have based ADL interventions On cognitive assessment, a biological model may be more accurate and less costly. In addition, AD is characterized by marked heterogeneity which mandates an individualized approach to assessment and care planning. Metter (1988) notes the need for additional research to clarify the heterogeneity of AD and recommends approaches that utilize clinical and [brain] scanning features to further understanding of disease differences. Ultimately, specific treatment approaches may prove useful in subgroups of AD. Clinicians use both neuropsychological testing and brain imaging to diagnose dementia. While neuropsychological assessment provides an indirect measure of brain functioning, there has been little research to link it with actual ADL/IADL functioning. Single-photon emission computed tomography (SPECT) is a state of the art imaging modality that utilizes commercially prepared radiopharmaceutical tracers to identify perfusion patterns in the brain. Although expensive, SPECT is less costly than a complete neuropsychological test battery, and correlates well with neuropathological findings. Impaired visuospatial ability, a common problem in AD, is one area that is assessable by neurocognitive testing, is linked to parietal lobe functioning, and is prerequisite for ADL/IAD competency. Dawson (1993) has linked spatial dysfunction to impaired hygiene, dressing, grooming, and movement, and studies have linked wandering and getting lost to parietal lobe dysfunction. This prospective pilot study will address the following question: What is the predictive value of right parietal lobe perfusion as measured by SPECT and performance on selected neurocognitive tests on IADL performance in patients with AD? The sample will consist of 24 patients with possible/probable AD. Parietal lobe perfusion will be measured by the perfusion rate of the right parietal lobe normalized to cerebellar perfusion. Neurocognitive assessment of parietal lobe function will be measured by standardized assessments of visuospatial ability including the WAIS-R Block Design and Object Assembly Tests, the Clock Drawing Test, The Stereo Reindeer 50-004, Benton Orientation to Line Test, Benton Facial Recognition Test, and Construction Scale of the Neurocognitive Status Examination. IADL functioning will be measured using the Dressing and Fine Motor subscales of the Structured Assessment of Independent Living Skills and The Spatial Disorientation Index derived from the Memory and Behavior Problem Checklist. A series of bivariate correlations will examine the relationship of parietal lobe perfusion with the variables in the study. The overall goal of this research program is to increase understanding of the underlying physiological basis of dysfunction to provide the basis for informed nursing assessment and interventions.